Saturday, September 24, 2016

Carp undergo 'reverse evolution' to get their scales back

Common carp, known also by its scientific name Cyprinus carpo, are scaly fish. However, there was a small group of carp that were selectively bred with no scales. European monks bred these carp to make the fish easier to cut open and cook. Also known as mirror carp, the species was initially introduced to Madagascar for fish farming purposes.

A carp

A recent study by The Royal Society shows that the population of mirror carp has declined since their introduction to Madagascar in 1912. Those carp have since evolved into scaly fish. Even though they still possess the genetic mutation that would give them smooth sides, the fish have scales. The article refers to this process as "reverse evolution", but I believe it is more of an environmental adaption. Scaled carp have better fitness; they are more likely to survive due to the scales' protection from predators and parasites. Therefore, the carp quickly adapted to their environment by evolving scales on their bodies. 

The process of the carp recovering scales took approximately one-hundred years. In the larger scheme of evolution, this adaption happened very rapidly. The environment heavily forced carp to recover scales. I believe this is a great example of observing selection through environmental adaptions, even though the fish were initially bred to not have a certain trait. Through scenarios like the common carp being bred without scales and relocated, we are able to see how beneficial evolution occurs within species due to environmental pressures, regardless of genetic modification.

Friday, September 23, 2016

Vikings Gave Us Smooth Riding Horses

            Have you ever ridden on a horse and the ride was just really “bumpy?” Chances are the horse you were riding on did not have the DMRT3 gene, otherwise known as the “gaitkeeper” gene.
Horses have long been a way in which human beings have been able to travel far distances. During the early centuries of mankind, horses were mostly used for transportation as well as a “vehicle” for riding into battle. Today, horses are prize animals showcased in equestrian competitions and the Olympics. Interestingly enough, there is one thing that you might not be able to see in Olympic competing horses: ambling. Why is that? The answer: Genes.
There is a certain breed of horses that are known to be able to amble, which is a type of gait that is not as fast as a gallop but faster than a walk which provides riders with a much smoother ride (See video for ambling). Evolutionary geneticist Arne Ludwig and others from the Institute for Zoo and Wildlife Research in Berlin analyzed DNA from the remains of 90 horses some of which dating back to the 9th century. They discovered that some of these horses contained this “gaitkeeper” gene which allowed horses to amble smoothly over long distances. This gene mutation was also found in early Icelandic horses but interestingly enough, not in any other horse remains found from the same time period in mainland Europe. The gene mutation DMRT3 has been viewed by researchers as a controller of the expression of genes in neurons that coordinate muscle movement allowing for the horses to amble.


Although just a theory, it is believed that the Vikings were the ones to first use these ambling horses and began to introduce them into the trading market of the 9th century as far as the Middle East and Caspian Sea. With that in mind, the introduction of ambling horses for transportation revolutionized journeys over long distances for humans. Not only did these ambling horses make traveling smoother, it also allowed travelers to journey longer without having to stop to rest from the “bumpy” ride of horses without the DMRT3 gene, making trips much faster. To this day, there are many breeds of horses that contain the DMRT3 gene. So the next time you want to go horse-back riding, get a genetic sequence of the horses to find the ones that will provide you with a smooth ride.

(http://www.nytimes.com/2016/08/11/science/horses-gaits-ambling-vikings.html)

The Vegetarian Gene

Plant-based diets are becoming increasingly popular because of their positive effect on personal health, environmental wellness, and ethical consumerism.  Although many of us choose to go plant-based for our own personal reasons, could there be a genetic component strengthening our craving for more fruits, vegetables, grains, and rice?

A group of researchers from Cornell recently conducted a study on the possibility a vegetarian gene.  The idea of the 'marine diet' found among the Inuit of Greenland sparked the interest in discovering a gene for the preference of primarily plant-based diets.  The relationship between genes and diet also opens the door to the possibility of structuring personalized diets based off of genetic information.  Knowing that my body is genetically designed to metabolize certain foods better than others might drive me to eat in a way that utilizes these adaptations in order to live my most healthful life.  

The vegetarian allele originally evolved in populations that consumed a generally plant-based diet such as India, Africa, and parts of Eastern Asia.  Those with this adaptation have an increased ability in processing omega-3 and omega-6 fatty acids.  These fats are easily converted into compounds that are essential for things like early brain development, blood pressure regulation, response to inflammation, and immune health.  This genetic variation was postivley selected for in these populations over hundreds of years.

The frequencies of these alleles were analyzed in 234 vegetarian Indians and 311 Americans.  It was confirmed that the vegetarian allele occurred in 68 percent of the Indians and only 18 percent of the Americans.  The 1,000 Genomes Project similarly found the vegetarian allele occurs in 70 percent of South Asians, 53 percent of Africans, 29 percent of East Asians, and 17 percent of Europeans.





Genetic Modification of Grains

In an article posted on ScienceDaily, it appears that scientists have found a new approach to genetic modification of grains. Genetically modified plants and a variety of foods have caused controversy, but research is still persistent on improving the techniques done to make GMO's possible. Over the years, it has not been easy to find a method of genetic modification for grain crops. Previously, methods have been tried using a bacterium called Agrobacterium which transfers DNA to its host genome and further stimulates tissues to regenerate into whole plants. The problem with this is that the bacterium infects a small range of grain cultivars.

Researchers at DuPont changed the game and increased the genetic modification rates for many of maize cultivars. This was done by adding morphogenic genes to the other genes being modified. In other research, morphogenic genes help production of embryonic tissue. With these increased numbers of maize cultivars the technique was tried and successful with sorghum, rice and sugarcane. I think this is a great breakthrough despite the controversy that genetically modifying something often causes. As our population expands, it is necessary to have large quantities of these amounts. With the use of transgenic plants and gene modification, the population of these plants can continue to grow and benefit humans as well as scientific research.

Gene Testing that lets Breast Cancer Patients Skip Chemo

      A new study performed by doctors in Europe have shown that not all breast cancer patients have to go through chemo therapy. The study shows that about half of woman with early stage breast cancer who would receive chemotherapy, actually don't need it and would have little to no risk of the cancer coming back.

      The study uses a genetic test called MammaPrint to look at 70 different genes involved in breast cancer growth. If 50 genes were active and 20 genes were inactive, the patient was considered high risk for cancer spread. If the patient had 20 active genes and 50 inactive genes, the patient was considered low risk for cancer spread.

     This test will be good for patients who fall into an area of uncertainty, mostly for patients who show high clinical risk but low genomic risk. The study included women with the most common type of breast cancer in its early stages that tested negative for a receptor called her2. The studied involved 6,693 women at 112 hospitals in 9 European countries. All patients had the usual initial treatments of surgery, hormonal therapy, and radiation. Then genomic testing was performed to see if the patient had a high or low risk for recurrence. Clinical features were also looked at such as tumor size and number of positive lymph nodes.

     Patients who had a high clinical risk but low genomic risk were of most interest in the study. 1,550 patients in this study fell into that category. These were assigned at random to be treated based on their clinical risk or genomic risk. Some patients received chemotherapy and others did not. The patients were then watched for the spread of cancer.

     After 5 years 94.4% of women who did not receive chemotherapy did not have distance spread of cancer and 95.9% of women who received chemotherapy had no distant spread. Based on this study, researchers conclude that it is safe for women with high clinical risk and low genomic risk to skip chemotherapy. An editorial the went along with this study noted that the study was not large enough and that more research needed to be done to say it is actually safe for women to skip chemotherapy.

     I found this article really interesting because it was talking about this use of genetics in the help of treating cancer. Women could now have the option to skip chemotherapy all together without enduring the harmful side effects of chemotherapy such as weight loss, hair loss, nausea/vomiting, infection, and other effects. This is a huge step in the treatment of breast cancer and in the future hopefully in the treatments of other types of cancer.

For more information on genetic testing in breast cancer please visit:


Thursday, September 22, 2016

Genetic Engineering: a Risk or a Benefit?

Genetic engineering has been a controversial issue for several years, for both health and ethical purposes. It involves the alteration of a gene using technology, usually for health, agricultural, and economic purposes. Throughout history, animal breeders have been selectively breeding their animals for certain desirable traits. However, this technique took decades in order to achieve these certain traits. Now, with modern technology, certain traits can be achieved instantaneously. Even though genetic engineering is used for a good cause, it might not always have the intended outcome.
 As shown in the picture above, the two calves had their genes altered when they were just single cells in a petri dish, so that they do not grow horns throughout their lifetime. This was an alternative to dehorning; a painful process performed by farmers in which they burn off the horn-buds and stop the growth of horns to prevent injuries. Some examples of Genetically Modified Organisms (GMOs) with more nutritious values are the strain of “golden” rice with a lot of beta-carotene (an antioxidant good for the eyes and skin), soybeans whose fats are more heart-tolerant and better for cooking, and meat with higher amounts of omega-3-fatty acids, which can help prevent heart disease, stroke, and cancer. Recently, researchers have reported that they edited Malaria-carrying mosquitoes so that they no longer carry the parasite. These are just a few examples of genetic engineering for good causes.

 On the other hand, there are many questions raised about genetic engineering. One of the most common questions asked is if food made from GMOs is “good for you.” Many scientists from the American Association for the Advancement of Science, however, say that GMOs are safe to eat. Another concern is the use of animal viruses in genetic engineering, which people worry that this could infect people or other animals. Because of this, the FDA (Food and Drug Administration) takes a different approach with GMO products in order to prevent spread of disease.

 I personally have mixed views on genetic engineering. I think that it can be very useful to the pharmaceutical industry and other biomedical fields, in which it could be used to help find new cures. However, a major concern I have about it is the impact it has on the animals being edited, like the increase in growth rate and early maturation, which could cause stress on the animals.  I also believe that if scientists are not careful, genetic engineering may have a disastrous outcome, even to the point where the GMOs are beyond control.

Links:


Worldwide Brain-Mapping Initiative

Brain-mapping is defined by the study of anatomy and function of the brain and spinal cord through imaging. Brain mapping has been around for a few years but now researchers will apply all data found "in a global push" to fully understand the brain. Researchers held a meeting hosted by the U.S National Science Foundation at Rockefeller University to discuss the main goals of this project. One goal is to have universal brain-mapping tools. Many scientists from all over the world have great equipment to perform experiments. However, scientists can perform experiments quite differently when not in the same environment. This, thus, makes it complicated to exchange data and information. If the data is too difficult to exchange, than other scientists will not be able to re-perform experiments in order to test how accurate the data is. Another major goal is to create an International Brain Observatory. In this observatory, scientists from all around the world will have access to compelling microscopes, and etc. Thus being a virtual cloud-base resource center for sharing information on the brain. However, some feel like there are resources that are being ignored. For example, a nine-year old CBRAIN program in Canada is very similar to the International Brain Station proposed at Rockefeller University. I think there is a reason why not every country participates in the CBRAIN Program. Professional scientists would not waste time and money if they did not have too. This new idea is more suitable for exchanging information in a calmly manner. There are also money concerns- who will pay for all technology? I believe that once scientists all around the world exchange data more efficiently, than humans will be able to understand the complex brain and how it works.

How did we get where we are now?

Where do you think your ancestors came from? Well, it is finally concluded that even if you're not from African descent, your ancestors most likely did in fact come from Africa. We all have ancestry from people who lived in Africa 50,000-80,000 years ago!
It is well known that humans evolved in Africa roughly 200,000 years ago. But how did they disperse and colonize different lands? This is the question that three different teams of researchers began to study. In order to fully understand human history, geneticists sequenced genomes of 787 people from indigenous populations like Basques, Mayans and Cree Indians. Although early studies of DNA draw conclusions that all non-Africans are all closely related, the main question the geneticists had was how humans expanded and spread from Africa.
A single strand of hair, about a century old, gave the answer partially away. With this single strand of hair, Dr. Willerslev and his team reconstructed the genome of an Aboriginal Australian. This info was enough to give away the fact that the ancestors of Aboriginal Australians arrived about 62,000 years ago in East Asia when they descended away from other non-Africans. After all three studies were done, the teams gathered enough information from sequencing the genomes of people from different indigenous populations  to conclude that ancestors of non-Africans split off about 65,000 to 200,000 years ago! Although their is a vast time difference, they concluded that the reason for humans leaving Africa in the first place was due to the rapidly changing climate, rainfall in particular. Humans followed the tracks of the rainfall into early Eurasia where their would be better sources of food. Therefore, next time you want insight into where your early ancestors came from, keep in mind that they all came in different waves from Africa to migrate towards different lands!
http://www.nytimes.com/2016/09/22/science/ancient-dna-human-history.html?rref=collection%2Fsectioncollection%2Fscience&action=click&contentCollection=science&region=rank&module=package&version=highlights&contentPlacement=1&pgtype=sectionfront&_r=0